Recently, foundation or hue cosmetics were variously disclosed and such foundation or hue cosmetics have been used while they are filled up in portable cosmetic containers for the purpose of portability as well as keeping convenience.
For example, a compact is provided as a foundation contained and kept in a cosmetic container which is formed to a predetermined shape, and put on a face while used by intermediate means such as a puff.
However, such a foundation includes a volatile solvent which is harmless to humans, and such a volatile solvent is evaporated into air if it is not properly sealed, so that the foundation gets hardened rigidly till it cannot be used any more.
Moreover, the original scent carried by such foundation or hue cosmetics is evaporated, so that characteristics of the cosmetics cannot be ensured for a long time.
For such reasons, the cosmetic container of the foundation or hue cosmetics has a sealing structure where an inside is isolated from the outside while a cover is shut in order to prevent deterioration of the cosmetics filled therein.
The cosmetic container provided with such a sealing structure mainly comprises a lower container main body, an inner container received in the container main body and filled with cosmetics, a puff selectively received on the inner container, and an outer cover having a side part hinged to an upper part of the container main body and the opposite part locked or unlocked by locking means to be open or closed.
In this case, to retain moisture and scent of the cosmetics received in the inner container, an additionally provided gasket of an elastic rubber material is supportedly installed on a supporting frame which is provided at an outside of the inner container. Also, a protruding rib is included to press an upper surface of the gasket when the outer cover is closed so that sealing is maintained therebetween.
However, such a conventional sealing structure requires additionally forming and assembling a packing of an elastic rubber material for maintaining the sealing of the inner container from the outside, so that productivity and assembling workability are lowered and the manufacturing cost rises.
To solve such problems, a cosmetic container having a sealing structure as shown in FIG. 1 has been disclosed.
That is, as shown in FIG. 1, an insert groove 3a is formed along an upper side of a supporting body 3 which is provided at an outside of an inner container 5 of a container main body 2. Rubber in a liquid state is filled and hardened in the insert groove 3a to form and fix a sealing hardened rubber 4. Therefore, when an outer cover 6 is closed and held by a push button 7 of a locking part to maintain a closed state, a rib 6a integrally formed on a bottom surface of the outer cover 6 is tight on the hardened rubber 4 to maintain sealing.
Such technology enables doubling the sealing ability with a simple structure by using the liquid rubber. Also, as the liquid rubber is filled and hardened to install the hardened rubber, there are advantages in reducing the manufacturing cost as well as improving the productivity and the assembling workability.
According to such a prior art, as shown in an expanded view of FIG. 1b, the hardened rubber 4 is hardened in a state of shrinking concavely at a center part thereof due to surface tension during the hardening of the liquid rubber which has been firstly inserted. As the rib 6a contacting a surface of the hardened rubber 4 is provided as a plastic protrusion harder than the hardened rubber 4, the sealing is accomplished by maintaining the hardened rubber 4 strongly pressed when the outer cover is in its closed state.
However, the hardened rubber 4 in a pressed state due to the rib 6a does not restore properly from the pressed state when the pressed state is released by opening the outer cover. That is, as shown in FIG. 1c, a groove 4a is formed in the hardened rubber due to a plastic deformation relating to fatigue strength and its deformation is enlarged due to a repetitive pressing contact of the rib 6a with a long-term use.
Moreover, as the rib 6a integrally formed in protrusion on the bottom surface of the outer cover 6 undergoes a twist deformation due to a temperature change after it has been formed, the rib 6a comes not to have a uniform contacting end surface.
In other words, though sealing force between the outer cover and the inner container is maintained in the early stage of use, a twist deformation of the outer cover, a shrinking deformation of the sealing ring and etc. in the long-term use generate coming-off at a part of the tight interface therebetween, so that the sealing of a receiving space of the inner container cannot be maintained.